Sealing device for nipples

ABSTRACT

A device for sealing leaks around pressure-tap nipples in a main pipeline without removing the line from service, comprising a split saddle having a bushing surrounding the nipple and clamped to the pipe by means of a band surrounding the pipe and overlying the saddle. Packing is inserted between the bushing and the nipple, and this packing is compressed into a sealing position by means of a split packing gland which surrounds the nipple and is drawn down onto the packing by means of upstanding studs secured to the saddle and passing through the packing gland.

United States Patent [191 Aulisa r July 17, 1973 SEALING DEVICE FORNIPPLES 3,687,490 8/1972 Dunmire 285/197 l, 7 [751 lnvenwn GerardA-flisa, claymom, Del. 3.183.332 11513333 2323551, ,1 2831 41 3 [73.]Assigneei Sun Oil Company, Philadelphia, Pa. I

Primary Examiner-Thomas F. Calllaghan 22 l d. 1, 7 1 1 F16 June 19 2Attorney-Ge0rge L. Church, Donald R. Johnson [21] Appl. No.: 263,371 at[52] US. Cl 285/15, 138/99, 285/197 [57] ABSTRACT [51] Int. Cl. F16155/16 a device for sealing leaks around pressurc4ap nipples [58] Fieldof Search 285/15, 16, 17, 197, in a i pipeline without removing the linefrom 235/171 337; 138,99; 29/401 402; 137/318 vice, comprising a splitsaddle having a bushing sur- 15; 251/145 146 rounding the nipple andclamped to the pipe by means of a band surrounding the pipe andoverlying the sad [56] References Cited dle. Packing is inserted betweenthe bushing and the UNITED STATES PATENTS nipple, and this packingis'compr'essed into a sealing 646,011 3/1900 7 Ster1ing..... 285/337position y means of a split P g gland which 608,6l3 8/ 1898 Linichrounds the nipple and is drawn down onto the packing 3,480,252 11/1969,Simons by means of upstanding studs secured to the saddle and 2,689,1429/1954 Glayzer 138/99 X passing through the gland 1 Claim, 3 DrawingFigures 25 25 754 r 2/ 22 S 1 E i- "a "I. y/ r 7 20 j 1' f 4 1 4 6 r i 6a r r 0" PAIENIE L JUL 1 7 mm I FIG. I. 7

SEALING DEVICE FOR NIPPLES This invention relates to a sealing devicefor pipe nipples, and more particularly to a device for sealing leaksaround pressure-tap nipples which are welded into flanges in a mainpipeline.

In order to measure certain pressures in a main pipe line, such as thepressures developed adjacent calibrated orifices mounted in a pipeline,pipe nipples serving as pressure taps, of small diameter compared tothat of the main line, are welded into flanges provided in the mainline, these pipe nipples extending in a generally radial direction withrespect to the main line, the inner ends of the nipples being coupled tothe interior of the main line and the outer ends of the nipples beingcoupled to suitable pressure transducers.

Occasionally, a leak develops around the outside of these nipples, whichresults in a safety hazard as well as an economic loss (due to loss ofvaluable hydrocarbon product from the main line). According to priorpractice, it was necessary to remove the main line from service (whichmeant shutting down the entire process unit, of which the main lineforms a part) in order to repair the leak. Such a shutdown is bothcostly and time-consuming.

An object of this invention is to provide a novel sealing device fornipples.

Another object is to provide an improved sealing device for pressure-tappipe nipples.

A further object is to provide a leak-sealing device for pressure-tappipe nipples which can be installed (applied) without removing the mainpipeline from service.

A still further object is to provide a novel leak-sealing device fornipples which is efficient and effective in operation.

The manner in which the foregoing objects are accomplished will be bestunderstood from the following detailed description of the invention,taken in conjunction with the accompanying drawing, wherein:

FIG. 1 is a plan view of the nipple sealing device of this invention, asassembled or installed;

FIG. 2 is a cross-section taken along line 2-2 of FIG. 1; and

FIG. 3 is a somewhat diagrammatic sectional view illustrating theconfiguration of the belly band.

Now referring to the drawings, the numeral 1 denotes a portion of thewall of a flanged main pipeline, the pipeline and the falnge beingillustrated as a single, integral member for the sake of convenience. Apipe nipple 2, whose diameter is small compared to that of the mainpipeline bore, serves as a pressure tap for the main line. Nipple 2 iswelded entirely through the flange and also through the wall of the mainline itself, such that the inner end of the nipple communicatcs with thebore or interior of the main line; the axis of nipple 2 extends in aradial direction (i.e., radial with respect to the main pipeline)through the flange and pipeline wall. Assuming that nipple 2 is servingas an (orifice) pressure tap, the outer end of this nipple (not shown)would be coupled to a suitable pressure transducer.

Occasionally, leaks develop around the outside of the nipple 2, in thearea of the weldment; such leaks permit fluid to escape from the mainpipeline into the atmosphere. The purpose of the device of thisinvention is to seal such a leak. The sealing device of the invention isapplied or installed while the main line is in service, that is, withoutshutting off the flow of fluid through this line.

When a leak develops around the orifice pressure-tap 2, a gasket 3,having a central aperture for nipple 2, is positioned around the nipple2, against the outer surface of flange 1; this gasket is made of asuitable resilient sealing material and should be of split or multipiececonstruction, so that it can be placed in position around thecylindrical outer wall of nipple 2.

A two-piece (or split) saddle member, denoted generally by numeral 4, ismounted in position overlying gasket 3; how this member is mounted willbe described hereinafter. The member 4, which is split into two halvestransversely of its length after it is completely fabricated, comprisesa centrally-apertured (to surround nipple 2) bottom plate or pad about3% inches in length curved to form a portion of a cylindrical surfacewhose curvature matches that of the outer surface of flange 1. At thecentral aperture in the bottom plate, and concentric therewith, member 4has an integral (actually, it may be welded to the bottom plate)upstanding bushing 5, about 54 inch long and with an I. D. of 1-1 [16inches, such as to loosely surround nipple 2. Saddle 4 has securedthereto four upstanding threaded studs 6, each about I-% inches long,each stud being threaded into the bottom pad of saddle 4 and then tackwelded in position. The studs 6 are preferably symmetrically locatedwith respect to the center line of saddle bushing 5, two being locatedon one side of the longitudinal center line of the composite saddle 4and on respective opposite sides of bushing S, and the other two beinglocated on the other side of the longitudinal center line of thecomposite saddle and on respective opposite sides of bushing 5.

In order to secure the two halves of saddle 4 together after this memberhas been positioned as described, two pairs of outstanding aligned earsare formed on this member, with one ear of each pair integral with (orwelded to) a respective half of the member, at a suitable location alongthe bushing 5. Ear pair 7 is located approximately centrally withrespect to one of the longer sides of the rectangular pad of member 4,and this ear pair has aligned clearance holes through which extends abolt 8 which has a nut 9 threaded thereon for tightly fastening togetherthe two ears of the pair 7, and thus also the two halves of saddlemember 4, at one side of the latter. Ear pair 10 is locatedapproximately centrally with respect to the other of the longer sides ofthe rectangular pad of member 4, and this ear pair has aligned clearanceholes through which extends a bolt 11 which has a nut 12 threadedthereon for tightly fastening together the two ears of the pair 10, andthus also the two halves of saddle member 4, at the other side of thelatter.

The composite or two-piece saddle member 4 is held in position by meansof a two-piece belly band 13 made of Ar-inch steel strap, for example.The juxtaposed upper (in FIGS. 1 and 3) ends of the two pieces of bandI3 are spaced about l- /fi inches apart, enough to clear the O. D. ofsaddle bushing S, and these two upper ends overlie the pad of member 4.The upper ends of the two pieces of belly band 13 are provided withclearance holes for studs 6, in order to attach the upper ends of thesetwo band pieces to saddle member 4. Thus, referring'to FIG.. 3, onebellyband piece (the right-hand piece in FIG. 3) has two stud clearanceholes centered on the aligned center lines 14 one of which is shown, atthe right-hand side of bushing 5. The other belly band piece (theleft-hand piece in FIG. 3) has two stud clearance holes centered on thealigned center lines 15 one of which is shown, at the left-hand side ofbushing 5.

The belly band 13 pieces pass around the outside of flange l (the twopieces passing around the flange in relatively opposite directions, asillustrated in FIG. 3), and at the opposite side of this flange(approximately diametrically opposite to nipple 2) each piece of theband has an outstanding ear, the two ears being aligned to provide apair 16. The ear pair 16 has aligned clearance holes through whichextends a bolt 17 which has a nut 18 threaded thereon for tightlyfastening the belly band 13 around the flange 1, and thus for tightlyclamping the saddle member 4 in position on flange 1.

When the parts mentioned have been mounted as previously described, andthe various nuts 9, 12, and 18 have all been tightened sufficiently,Teflon packing material 19a is inserted in the (narrow) annular spacebetween the outside of nipple 2 and the inner face of saddle bushing 5.The packing material 19a should be of split or multi-piece construction,so that it can be placed in position around the cylindrical outer wallof nipple 2. In order to hold the packing material 19a in place, and tocompress it to stop the leak, a two-piece (or split) packing gland,denoted generally by numeral 19, is utilized. The gland 19, which issplit into two halves longitudinally of its length after it iscompletely fabricated, comprises a centrally-apertured (to closelysurround nipple 2) base plate about four inches in length and, at itscenter and aligned with the aperture,

an integral (or welded) downwardly-extending cylindrical shell 20 (l. D.0.860 inch, and about inch long) adapted to closely surround nipple 2and to bear at its lower end against the upper end of packing 19a.

In order to secure the two halves of gland 19 together after it has beenpositioned around nipple 2, above packing 19a and saddle bushing 5, twotie bars 21 and 22, one at each respective opposite end of the compositegland 19, are employed. Tie bar 21, of rectangular cross-section, spansthe joint between the two halves of gland 19 at one end thereof; twoscrews 23 pass through clearance holes in tie bar 21 and thread intoaligned tapped holes provided in the two respective halves of gland 19.Tie bar 22, of rectangular crosssection, spans the joint between the twohalves of gland 19 at the other end thereof; two screws 24 pass throughclearance holes in tie bar 22 and thread into aligned tapped holesprovided in the two respective halves of gland l9.

The base plate portion of gland 19 has four clearance holes, arranged toaccommodate therein the respective studs 6; nuts 25 are threaded ontothe upper ends of these studs, above gland 19. Nuts 25 are tightened todraw the gland shell 20 down onto packing 19a,,to thereby compress thelatter into sealing position around nipple 2 and against saddle bushingS.

It is pointed out that the nipple sealing device of the presentinvention is intended to be applied or installed without removing themain line from service, which is to say while the leak around the nippleis leaking. The split or two-piece construction of the various memberssuch as 4, 19, etc. enables this to be accomplished with ease.

The invention claimed is:

l. A sealing device for a nipple which extends outwardly through a pipeflange, comprising a saddle member having a pad portion adapted tooverlie the outside of said flange and also having a cylindrical bushingadapted to surround said nipple, said saddle member being split into twohalves; means for detachably securing together the two halves of saidsaddle member, thereby to form in effect a unitary member; a splitgasket positioned between the outside of said flange and said saddle padportion, surrounding said nipple, packing means positioned between theinner wall of said bushing and the outside of said nipple, a packinggland having a portion closely surrounding said nipple, said glandportion being movable to engage said packing means and to cause it toprovide a seal in the annular space between said bushing and the outside.of said nipple, said packing gland being split into two halves; meansfor detachably securing together the two halves of said packing gland,thereby to form in' effect a unitary gland; threaded elements couplingsaid packing gland to said saddle pad portion, thereby to enable saidgland portion to be moved'into seal-providing engagement with saidpacking means; two separate aligned arcuate members extendingcircumferentially around said flange, in tight engagement with the outersurface thereof, one end of each of said last-mentioned members engagingrespective threaded elements on said saddle pad portion; and meansfastening together the other ends of the two last-mentioned members.

1. A sealing device for a nipple which extends outwardly through a pipeflange, comprising a saddle member having a pad portion adapted tooverlie the outside of said flange and also having a cylindrical bushingadapted to surround said nipple, said saddle member being split into twohalves; means for detachably securing together the two halves of saidsaddle member, thereby to form in effect a unitary member; a splitgasket positioned Between the outside of said flange and said saddle padportion, surrounding said nipple, packing means positioned between theinner wall of said bushing and the outside of said nipple, a packinggland having a portion closely surrounding said nipple, said glandportion being movable to engage said packing means and to cause it toprovide a seal in the annular space between said bushing and the outsideof said nipple, said packing gland being split into two halves; meansfor detachably securing together the two halves of said packing gland,thereby to form in effect a unitary gland; threaded elements couplingsaid packing gland to said saddle pad portion, thereby to enable saidgland portion to be moved into seal-providing engagement with saidpacking means; two separate aligned arcuate members extendingcircumferentially around said flange, in tight engagement with the outersurface thereof, one end of each of said last-mentioned members engagingrespective threaded elements on said saddle pad portion; and meansfastening together the other ends of the two last-mentioned members.